Small Animal SPECT Using a Skew-Slit Collimator

使用斜缝准直器的小动物 SPECT

• 批准号: 7471761
• 负责人: G LAWRENCE ZENG
• 金额: $ 18.78万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7471761
• 关键词: Achievement; Algorithms; Animals; Applications Grants; Area; Arts; Blur; Categories; Collimator; Computer Simulation; Data; Data Set; Detection; Development; Disadvantaged; Evaluation; Evaluation Studies; Facility Construction Funding Category; Fatty acid glycerol esters; Financial compensation; Funding; Goals; Hand; Image; Measurement; Methods; Modeling; Morphologic artifacts; Noise; Numbers; Ocular orbit; Performance; Pliability; Positioning Attribute; Public Health; Resolution; Retinal Cone; Risk; Rotation; Severities; Source; System; Technetium 99m; Testing; Thinking; Three-Dimensional Image; Three-Dimensional Imaging; Validation; Weight; Width; attenuation; base; concept; design; detector; image reconstruction; improved; innovation; new technology; novel; reconstruction; research study; single photon emission computed tomography; success; theories

DESCRIPTION (provided by applicant): The main objective of this project is the development and evaluation of small animal SPECT (single photon emission computed tomography) using skew-slit collimators. The state-of-the-art configuration for small animal SPECT imaging uses a pinhole or a multi-pinhole collimator. We propose the use of a skew-slit collimator to replace the pinhole or multi-pinhole collimator, in order to significantly reduce image artifacts and increase transaxial resolution. A pinhole forms a cone-beam imaging geometry. If the collimator rotates around the object (e.g., a small animal) in a circular orbit, the projection measurements acquired by the cone-beam imaging geometry are incomplete and not enough for an artifact-free image reconstruction. The severity of the artifact is proportional to the cone-angle of the pinhole in the direction of the axis of rotation. By transforming a pinhole into a pair of skew slits, the imaging cone-angle can be controlled by the distances of the two slits to the detector. We are able to use a large cone-angle in the transaxial direction to increase image magnification, and a small cone-angle in the direction of axis of rotation in order to reduce the data-insufficiency artifacts. This is achieved by placing a vertical slit (that is, the slit is parallel to the axis of rotation) close to the object and placing a horizontal slit farther out. The multi-pinhole collimator is able to significantly reduce the cone-beam artifacts and to increase the detection sensitivity by tiling the detector with multiple cone-beam images. To avoid multiplexing as much as possible, the cone-beam image magnification in the multi-pinhole collimator is smaller than that in the single- pinhole. The smaller image magnification could result in poorer spatial resolution. We therefore propose a multiple-skew-slit collimator that has one vertical slit and several horizontal slits. Compared with the multi- pinhole system, the multi-skew-slit system has a larger image magnification in the transaxial direction, and thus has better image resolution. This grant application promotes the development of very novel technologies in small animal imaging. While we show great potential for the skew-slit system in theory, further development of reconstruction algorithms and construction and testing of an actual physical system are required to move this idea into a lower risk category suitable for R01 type funding. A key goal is to generate preliminary data from a physical skew-slit system. Success in the aims here will provide evidence that skew-slit SPECT systems offer substantial improvements for small animal applications. The achievements will naturally form the basis for an R01 for rigorous evaluation and further optimization and improvements. PUBLIC HEALTH RELEVANCE: This project proposes a novel SPECT imaging system that has the potential to outperform the state-of-the-art pinhole imaging system. Our system uses perpendicular slits to replace the pinholes. As a result, the image resolution is improved. It means that we can see smaller objects. This new system will be very important in small animal imaging.

描述（由申请人提供）：该项目的主要目的是使用偏斜的准直仪的小动物SPECT（单光子发射计算机断层扫描）的开发和评估。小动物Spect成像的最新配置使用针孔或多针孔准直仪。我们建议使用偏斜的准直仪代替针孔或多针准直仪，以显着减少图像伪影并增加持续分辨率。针孔形成锥束成像几何形状。如果准直仪围绕圆形轨道围绕物体旋转（例如，小动物），则锥形束成像几何形状获得的投影测量值不完整，不足以进行无刻度的图像重建。伪影的严重程度与旋转轴方向的针孔的锥角成正比。通过将针孔转换为一对偏度缝隙，可以通过两个缝隙与检测器的距离控制成像锥角。我们能够在跨轴向方向上使用大型锥角来增加图像放大倍数，并在旋转轴方向上使用小锥角，以减少数据不足货物。这是通过将垂直缝隙（即，狭缝平行于旋转轴平行）来实现，并将水平缝放在较远的位置。多针孔准直仪能够显着减少锥形束伪像，并通过用多个锥形梁图像铺平检测器来提高检测灵敏度。为了避免尽可能多的多路复用，多针孔准直仪中的锥形梁图像放大倍数小于单针孔中的锥形图像。较小的图像放大率可能导致空间分辨率较差。因此，我们提出了一个具有一个垂直缝隙和几个水平缝隙的多间隙缝合物。与多针孔系统相比，多旋转系统在跨轴向方向上具有更大的图像放大倍数，因此具有更好的图像分辨率。该赠款应用促进了小动物成像中非常新颖的技术的发展。虽然我们在理论上表现出偏斜系统的巨大潜力，但需要进一步开发重建算法以及对实际物理系统的构建和测试才能将这一想法移至适合R01类型资金的较低风险类别。一个关键目标是从物理偏斜系统中生成初步数据。在此目的中的成功将提供证据，表明偏斜的SPECT系统为小动物应用提供了实质性改进。这些成就自然将构成R01的基础，以进行严格的评估以及进一步的优化和改进。 公共卫生相关性：该项目提出了一个新颖的Spect Imaging系统，该系统有可能超越最先进的针孔成像系统。我们的系统使用垂直缝隙代替针孔。结果，图像分辨率得到了改善。这意味着我们可以看到较小的对象。在小动物成像中，这个新系统将非常重要。